Raw and heat-processed partially defatted peanut flour, sorghum flour, and their composite flour had different functional properties (water and oil absorption, viscosity, gelation, emulsion capacity, nitrogen solubility index [NSI] and protein dispersibility index). Water and oil absorption increased with heat processing; this effect was more pronounced in peanut than in sorghum flour. Sorghum flour samples attained a viscosity peak of 630 BU when raw and 438 BU when heat-processed. Peanut fortification reduced the viscosity peak of sorghum flour. The NSI and emulsion capacity of sorghum flour improved considerably as a result of fortification. Heat-processing reduced the NSI and emulsion capacity of peanut flour and peanut-fortified sorghum flour. The implication of these results will be realized in designing protein-enriched products based on sorghum flour, especially for sorghum-growing regions of the world.

Grain sorghum [Sorghum bicolor (L.) Moench] has become a major dryland crop for the Great Plains, but information on production in rotations is limited. This study was conducted to determine N fertilizer recovery and use by grain sorghum in monoculture and rotational systems. Grain sorghum was grown under rainfed conditions on a Sharpsburg silty clay loam (fine, montmorillonitic, mesic, Typic Argiudoll) in: (i) continuous grain sorghum monoculture, (ii) a 2-yr soybean [Glycine max (L.) Merr.]-grain sorghum rotation, (iii) a 4-yr rotation of soybean-corn [Zea mays L.]-oat [Avena sativa (L.)] + clover [80% Melilotus officinalis (L.) and 20% Trifolium pratense (L.)]-grain sorghum, and (iv) a 4-yr rotation of oat + clover-corn-soybean-grain sorghum at Mead, NE. Broadcast applications of 15N-depleted NH4NO3 were made at 90 and 180 kg N ha(-1) in 1985 and 1986 to evaluate N fertilizer recovery. Fertilizer N recovery determined by isotopic methods was significantly higher for grain sorghum in monoculture (64.9%) vs. grain sorghum in rotation (54.9%). Fertilizer N recovery estimated by the difference method ranged from 118.5% in continuous grain sorghum to 9.1% in sorghum following oat + clover. Differences in N-recovery results by the isotope and difference methods indicated N fertilizer applied to grain sorghum in various cropping systems appeared to be entering different organic soil-N pools. These results substantiate the importance of the mineralization-immobilization turnover (MIT) effect in N-isotope experiments and the necessity for careful interpretation of N-recovery results, especially between complex cropping systems.

Grain sorghum [Sorghum bicolor (L.) Moench] has become a major dryland crop for the Great Plains, but information on production in rotations is limited. This study was conducted to determine N fertilizer recovery and use by grain sorghum in monoculture and rotational systems. Grain sorghum was grown under rainfed conditions on a Sharpsburg silty clay loam (fine, montmorillonitic, mesic, Typic Argiudoll) in: (i) continuous grain sorghum monoculture, (ii) a 2-yr soybean [Glycine max (L.) Merr.]-grain sorghum rotation, (iii) a 4-yr rotation of soybean-corn [Zea mays L.]-oat [Avena sativa (L.)] + clover [80% Melilotus officinalis (L.) and 20% Trifolium pratense (L.)]-grain sorghum, and (iv) a 4-yr rotation of oat+clover-corn-soybean-grain sorghum at Mead, NE. Broadcast applications of ¹⁵N-depleted NH₄NO₃ were made at 90 and 180 kg N ha⁻¹ in 1985 and 1986 to evaluate N fertilizer recovery. Fertilizer N recovery determined by isotopic methods was significantly higher for grain sorghum in monoculture (64.9%) vs. grain sorghum in rotation (54.9%). Fertilizer N recovery estimated by the difference method ranged from 118.5% in continuous grain sorghum to 9.1% in sorghum following oat+clover. Differences in N-recovery results by the isotope and difference methods indicated N fertilizer applied to grain sorghum in various cropping systems appeared to be entering different organic soil-N pools. These results substantiate the importance of the mineralization-immobilization turnover (MIT) effect in N-isotope experiments and the necessity for careful interpretation of N-recovery results, especially between complex cropping systems. Joint contribution of USDA-ARS and the Nebr. Agric. Res. Div., Journal Series No. 9213.

Sweet sorghum [Sorghum bicolor (L.) Moench] is a potential feedstock for ethanol production in many regions of the world. The objective of this study was to compare sweet sorghum cultivars with maize (Zea mays L.) as alternatives for ethanol production in the northern Corn Belt. Thirteen sweet sorghum cultivars were compared with an adapted maize hybrid grown on clay loam soils (Aquic or Typic Ha-pludols) in a randomized complete block design in 1987 and 1988. The fermentable carbohydrate content, or Brix (°B), of sorghum stalk sap was measured with a refractometer, and ethanol yields were calculated assuming 14.7 pounds fermentable carbohydrate per gallon ethanol. Ethanol yield from maize was calculated from the harvested grain assuming 22.4 lb maize grain per gallon of ethanol. Sorghum cultivars varied significantly in dry matter production, °B, fermentable carbohydrate yield, and ethanol yield. The best sorghum cultivars (Keller, Dale, and Smith) produced more ethanol than maize in 1988, a dry year, and were similar to maize in 1987, a more normal year. Averaged over both years, public cultivars Keller, Dale, and Smith were superior to most other sorghum cultivars or hybrids. Lodging was most severe for the sweet sorghum cultivars with the highest fermentable carbohydrate yields. Sweet sorghum appears to be a viable alternative source of ethanol compared with maize for the northern Midwest, but high fermentable carbohydrate, lodging resistant cultivars are needed.

Sweet sorghum [Sorghum bicolor (L.) Moench] is a potential feedstock for ethanol production in many regions of the world. The objective of this study was to compare sweet sorghum cultivars with maize (Zea mays L.) as alternatives for ethanol production in the northern Corn Belt. Thirteen sweet sorghum cultivars were compared with an adapted maize hybrid grown on clay loam soils (Aquic or Typic Hapludols) in a randomized complete block design in 1987 and 1988. The fermentable carbohydrate content, or Brix, of sorghum stalk sap was measured with a refractometer, and ethanol yields were calculated assuming 14.7 pounds fermentable carbohydrate per gallon ethanol. Ethanol yield from maize was calculated from the harvested grain assuming 22.4 lb maize grain per gallon of ethanol. Sorghum cultivars varied significantly in dry matter production, Brix, fermentable carbohydrate yield, and ethanol yield. The best sorghum cultivars (Keller, Dale, and Smith) produced more ethanol than maize in 1988, a dry year, and were similar to maize in 1987, a more normal year. Averaged over both years, public cultivars Keller, Dale, and Smith were superior to most other sorghum cultivars or hybrids. Lodging was most severe for the sweet sorghum cultivars with the highest fermentable carbohydrate yields. Sweet sorghum appears to be a viable alternative source of ethanol compared with maize for the northern Midwest, but high fermentable carbohydrate, lodging resistant cultivars are needed.